linux-kernel - Re: [PATCH v2] arch/x86: get rid of KERN_CONT in show_fault

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Date:   Mon, 25 Jun 2018 08:03:55 -0700
From:   Joe Perches <joe@...ches.com>
To:     Dmitry Vyukov <dvyukov@...il.com>, tglx@...utronix.de,
        mingo@...hat.com, x86@...nel.org, linux-kernel@...r.kernel.org,
        sergey.senozhatsky.work@...il.com
Cc:     Dmitry Vyukov <dvyukov@...gle.com>
Subject: Re: [PATCH v2] arch/x86: get rid of KERN_CONT in show_fault_oops()

On Mon, 2018-06-25 at 14:38 +0200, Dmitry Vyukov wrote:
> From: Dmitry Vyukov <dvyukov@...gle.com>
> 
> KERN_CONT leads to split lines in kernel output
> and complicates useful changes to printk like
> printing context before each line.
> 
> Only acceptable use of continuations is basically
> boot-time testing.
> 
> Get rid of it.
> 
> Signed-off-by: Dmitry Vyukov <dvyukov@...gle.com>
> 
> ---
> 
> Changes since v1:
>  - use pr_alert() instead of printk(KERN_ALERT)
> ---
>  arch/x86/mm/fault.c | 10 +++-------
>  1 file changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
[]
> @@ -671,13 +671,9 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code,
>  			printk(smep_warning, from_kuid(&init_user_ns, current_uid()));
>  	}
>  
> -	printk(KERN_ALERT "BUG: unable to handle kernel ");
> -	if (address < PAGE_SIZE)
> -		printk(KERN_CONT "NULL pointer dereference");
> -	else
> -		printk(KERN_CONT "paging request");
> -
> -	printk(KERN_CONT " at %px\n", (void *) address);
> +	pr_alert("BUG: unable to handle kernel %s at %px\n",
> +		(address < PAGE_SIZE ? "NULL pointer dereference" :
> +		"paging request"), (void *) address);

Perhaps remove the used-once KERN_CRIT uses of
nx_warning and smep_warning strings and maybe the
unnecessary parentheses and spaces used here too.